Spinal cord injury
Clinical presentation is related to the level of spinal cord injury. Classification of spinal cord injuries is typically performed based on the American Spinal Injury Association (ASIA) grading system, with grade A being a complete injury and grades B through D representing less severe injuries. Injuries may also be defined by the level of the vertebral injury (eg, C5 or L1), but it should be noted that the vertebral level is not the same as the spinal cord level, due to the vertebral column extending beyond the length of the spinal cord, which ends at L2-L3.
Other descriptors include tetraplegia, referring to an injury in the cervical region with associated loss of muscle strength in all 4 extremities, and paraplegia, with an injury to the spinal cord in the thoracic, lumbar, or sacral segments leading to loss of muscle strength in the lower extremities.
Injury at the level of C4 or above will result in impairment of respiratory function and need for intubation because of diaphragm paralysis due to compromise of the phrenic nerve, consisting of nerve roots from C3-C5. Lower cervical and upper thoracic injuries may also involve some degree of respiratory dysfunction due to paralysis of many intercostal / chest wall muscles.
Initially, spinal cord injury results in flaccid paralysis, change in sensation, loss of reflexes, and/or loss of bowel / bladder function. When accompanied by hypotension and bradycardia, this is often referred to as "spinal shock."
Over a period of days to weeks after a severe injury, the examination findings will change to spastic extremities, brisk reflexes, and urinary retention, often requiring catheterization.
Disruption of the autonomic nervous system, more specifically sympathetic function, occurs if the cervical or thoracic cord is injured. In settings of severe injury, after spinal shock wears off, autonomic dysreflexia can occur, which results in episodic sweating, flushing, hypertension, and reflexive bradycardia.
S14.109A – Unspecified injury at unspecified level of cervical spinal cord, initial encounter
S24.109A – Unspecified injury at unspecified level of thoracic spinal cord, initial encounter
S34.109A – Unspecified injury to unspecified level of lumbar spinal cord, initial encounter
S34.139A – Unspecified injury to sacral spinal cord, initial encounter
90584004 – Spinal cord injury
Differential Diagnosis & Pitfalls